The present invention relates to bakery trays that are generally rectangular with high end walls, lower side walls, and a bottom so that they may be cross-nested at a 90 degree orientation. The trays are further provided with interengaging feet and rails so that they may be stacked at high and low positions with 180 degree orientation and like orientation.
These trays are moved about singularly and in stacks by sliding across floors and other surfaces, and by movement along conveyors, such as roller or wheeled conveyors. The trays are also manually handled, for example by being stacked in various orientations in large stacks at different locations, including within a truck. Such stacks sometimes reach a height greater than the height of the person doing the stacking, at which time the stacking of the next highest tray is done overhead and termed blind stacking. During blind stacking, it is very common to have various portions of the trays hang up by interfering engagement to provide excess forces or to stop the sliding. Such stopping or excess forces can become quite annoying to the operators, produce forces that would topple a stack of trays, and generally increase handling time.
These trays are used in great volume by large bakeries, distributors and retailers, so that small differences tend to take on large proportions when multiplied by the volume of trays in use. For example, a small annoyance or small delay in blind stacking becomes very large when repeated thousands of times, where there are tens or hundreds of thousands of trays within one distribution system.